1. Field of the Invention
The present invention relates to a machine to reproduce a key onto a key blank and, more particularly, to a key regenerating machine in which the master key is optically analyzed, the appropriate key blank determined, and the bitting pattern regenerated or duplicated onto the key blank.
2. Background Art
It is well known in the art to duplicate keys, referred to as master keys, onto a key blank. The process first involves the operator identifying the master key. This process can be difficult, particularly for someone with little training or experience in the art. For example, there is a choice of over three hundred key blanks to evaluate. Many of the differences between two key blanks can be very subtle, compounding the operator""s difficulty. Thus, the possibility exists that even an experienced operator could chose the incorrect key blank to use for duplicating the master key.
Once the key blank is selected onto which the master key is to be reproduced, the pattern of the master key is usually traced while concurrently cutting the key blank. That is, a tracer or feeler gauge, which engages the bitting pattern of the master key, is mechanically linked to a cutting wheel, which cuts the bitting pattern into the key blank. As the tracer moves relative to the blade of the master key, the cutting wheel also moves, thereby duplicating the master key onto the key blank. The duplicate key will not be better than the master key although it could be worse. For example, if the linkage between the tracer and the cutting wheel for the key blank is off by a couple of hundredths of an inch, the duplicate could be inoperable. Also, the key could be worn from use so that the cut depths are no longer within factory specifications. These prior art key duplicating devices produce copies that are, at best, as good as the original and typically introduce duplication errors in the depths and/or spacing of the key bitting.
It is therefore an object of the present invention to provide an apparatus and method for improving the art of key reproduction. The present invention provides many improvements over the prior art to obtain this objective.
One aspect of the present invention is identifying the type of key blank onto which the master key is to be reproduced. The preferred embodiment determines the type of blank from a set of more than three hundred different types of blanks, and information about more than four hundred key silhouettes since each blank type may have multiple master key silhouettes. The preferred embodiment performs this by extracting information from digitized images of the master key and comparing the information to a database of key blanks. In the preferred embodiment, the information about the master key is obtained by backlighting the master key and digitizing the image and/or directing a substantially planar light beam, such as a laser, at a portion of the master key and digitizing the image of the intersection thereof. Algorithms compare the information of the master key to reference keys in the database and elimination those that are different, thereby leaving one correct match or a small subset of keys ranked by the likelihood of a match.
The result of the identification process is then conveyed to the operator who verifies the results of the analysis. If the operator does not agree with the determination, the present invention also presents the other likely matches, in order of likelihood of matching. Therefore, instead of trying to narrow down the type of key blank to use to duplicate a master key from over three hundred choices, the operator is presented with the most likely match. The present invention, accordingly, saves man-hours and improves accuracy.
Once the correct key blank is determined, the present invention then obtains information about the bitting pattern, which is the series of cuts in the blade of the master key. The preferred embodiment of the present invention preferably digitizes the information by backlighting the master key. The preferred embodiment also uses information in the database about each of the reference keys, such as manufacturers"" information about the locations of the cuts and the depths of each cut (or the width of the key at the location of the cut).
The preferred embodiment of the present invention then uses this information to modify the measured information about the master key. That is, the depths of the cuts (or widths of the key at the location of the cuts) are modified to be the closest or most likely cut depth from the factory specifications. This adjusted information is communicated to the cutting algorithm that is used to cut the pattern of the bitting pattern into the key blank. Therefore, the master key is xe2x80x9cregeneratedxe2x80x9d because the bitting pattern is cut into the key blank at the locations and depths that the key manufacturer establishes. Alternatively, if information is not in the database for the master key, then the cutting algorithms use the image of the master key to xe2x80x9cduplicatexe2x80x9d the pattern onto the key blank so that the bitting pattern is the same as that in the master key.
Other aspects of the present invention include using aligning jaws to place the key blank at a known position for cutting. Unlike devices in the prior art, the alignment jaws of the present invention can be moved independent of each other and be located at a predetermined position without continuous positional feedback.
Still another aspect of the present invention is using a gripper to hold the key at a predetermined position during cutting. The gripper holds most keys so that there is no lateral deflection during cutting, even when cutting the portion of the key blank farthest from the gripper. In the preferred embodiment, the gripper is biased to the closed position to hold the key, as opposed to a device using an actuator to force the portions of a gripping device together.